Luke: Box specs?

[NeoMishMoo]

Starting building my crappy adaptation on Luke's design yesterday, but after seeing these pictures I'm really craving the real thing!

[StereoInstaller1]

Well, check this out:



Yeah, there is plenty of room on the plate, but none between the woofer and ports, and then again no spare space around the hole of the pass through...getting the ports and the woofer on that panel is a squeeze.

Another thing you might wanna think about is the placement of the end of your port tube inside the box.

The opening being perpendicular to the face of the woofer is like blowing across the top of a bottle.

[mrbobian]

Huh... Well I don't know then. Since I didn't know how wide it has to be yet I used 11.5'' and the rest as well is VERY carefully and precisely drawn to scale. The only sad thing is I don't have the car around yet to do some real measurements...

[StereoInstaller1]

Like a foot or so? Fuck, I dunno. It has to fit my jig precisely, measuring days were long ago.

[mrbobian]

Humm... How wide is the "faceplate" thing that recesses the driver in that picture?

[StereoInstaller1]

That won't fit.

There isn't room to fit a 4" port and a 10" woofer in the opening of the ski pass.

Nice try though! Look at this pic, see how crowded it is already?

[mrbobian]

Yes I did. 0.12ft^3 for the driver and 0.368ft^3 for the port displacement...

It looks a little awkward too because I made the OD of the PVC 5in in the draft because that is the biggest part if I use the bends.

[SoEm0]

That is pretty beasty. Did you calculate in the sub/port displacement?

[mrbobian]

Spent quite a bit of time drawing things up in NX5 and tweaking here and there. It was quite the process of getting a whole lot into a small space.

I worked it out to be a gross vol. of 1.56ft^3 and with the maximum port length (39in) I get about a 1.08 net volume. Using 4in PVC puts me right around 27.5hz , being the lowest I can go. Im thinking I can build it and play around with port length until I get it sounding exactly how I want it.

I still have some fitment issues to work out with the magnet hitting the bottom of the box but I need to actually get the mag diameter to do that...
Also I need to measure the actual space in the trunk to figure our how big the "faceplate" thing needs to be and where it goes. Tell me what you think:

[foglght]

I'm not sure what the box was designed for as far as woofer, but generally I can get decent predictions (minus transfer function/cabin gain) with winisd.

I can't tell what the box is designed for, an 8 or a 10. I have plenty of 10's hangin around. Might try and build one sometime soon for a sealed ED 110v.2, or the Diamond D6.

More interested right now in getting the doors all situated. I REALLY wanted to do kicks, but its tight down there, and I actually use my dead pedal.

[mrbobian]

Actually, I would start right at 35Hz on that woof...the Fs is higher than I would normally want to see, but with .36 Qts, it should work well.

Still, it is only gonna cost you $5 more to make your tuning adjustable, so why not?

Alright. I will deff take your word on this one. I have a few weeks before I actually begin construction (away at college right not) but plan on getting going as soon as finals are done. I'll be sure get pictures and post up everything one here. Thanks for all your help. I'm sure I'll have plenty more questions to come too.

Mike B.

[StereoInstaller1]

Luke, thanks so much for the info. Please please don't let anything out that you don't want to. I totally respect what you on here and don't want to offend you or anything.
With that said, I totally did not even think about the "cab gain" or whatever the hell the term is for it. You are dead on with the S10 peaking like hell at around 60hz. I HATE HATE peaky bass around 60-80hz, I like LOW, smooth bass which is why I was shooting for 27hz. You said I would want to tune higher in this situation but won't I be forced to set my high pass to appox the tuning of the enclosure and then I'd pretty much lose anything below that? A sub would be no fun if you couldn't hit the low note in "Put On." I'm a real noob to audio but trying hard to learn. Any help would be appreciated. So I don't have a clue as to what I should tune to if E30s are typical for peaking around 40 and 100hz. My driver is an Fi Q10 powered by a Sundown 1000D. Here are the specs of the driver:

DUAL 1 | DUAL 2 Fs: 34.1 Hz | 34.0 Hz Re: 0.70 Ohms/coil | 1.4 Ohms/coil Qms: 7.31 | 7.38 Qes: .37 | .37 Qts: .36 | .36 Mms: 230g | 2235g Cms: .88mm/N | .88mm/N Sd: 310cm^2 | 310cm^2 Vas: 11.8 l | 11.8 l Spl: 83.3dB 1W/1m | 83.2dB 1W/1m Bl: 13.9 N/A | 19.6 N/A Xmax: 28mm Rms: 1000W Sealed box: .2-.6 cuft HQTS Ported box: .5-1.2 cuft @ 28-33Hz Sub OD: 11.000” Cut ID: 9.250” Mounting depth: 6.500” Displacement: 0.12cuft

I don't know 3/4 of the stuff on that list means. What are your suggestions I try and tune to if you don't mind? Thanks!


Mike B.

Actually, I would start right at 35Hz on that woof...the Fs is higher than I would normally want to see, but with .36 Qts, it should work well.

Still, it is only gonna cost you $5 more to make your tuning adjustable, so why not?

[87e30]

Luke, you're the man. That is all.

[mrbobian]

Mike, if I could actually draw the box out for you, I would. It is still a "cut and fit" proposition,. even though I use templates and such, I don't know the measurements!

The outside specs are:
W: 36"
H: 15" (dead nuts on, taller or shorted and you have issues)
Bottom Depth: 10"
Top Depth: 4"

If you build out of 3/4 MDF, that will give you a gross air space of 1.5 cubic feet.

The woofer is offset by a couple of inches, as the trunk is offset. There is a big old wire running down the left side and that is a bit of an issue...so if you get to measuring and find your woofer having an 18" C/L, it is WRONG!!!

Now, let me warn you: I will not divulge all of my tuning info. Hell, I have 20 years into learning how to make awesome bass in an E30...but WTF, have at it.

I can tell you this: if you can find a woofer that will handle over 25 watts RMS in a box tuned to 27Hz in an E30, I will be shocked. Your old S10 with that HUGE 60Hz bump is not the same here...in fact, damn near opposite. No output from 60 to 80, then a peak at 100...but a big old bump at 40 means you tune higher than normal given the airspace.

So, if you do 2 3" ports, it isn't hard to make them adjustable. Just make the quite short (like 60Hz tuning) and then make longer tubes you can add on.

If you were to find say, an old school Becker woofer with a Qts around .19 and a Fs about 22Hz, with a VAS way the hell out there like 300 liters, I could maybe see like a tuning in the range of 30hz...but you better make that box more like 4 cubic feet!

So, in honor of you asking me to divulge my 30 years of professional experience on your very first post, tear it up!

Post pics, make me proud!

Hey man, that is just fine, and thank you so much for protecting my interests.

I believe in open source stuff when possible, plus all the stuff I have learned in here makes it worth it.

You are a good man!

Luke

Luke, thanks so much for the info. Please please don't let anything out that you don't want to. I totally respect what you on here and don't want to offend you or anything.
With that said, I totally did not even think about the "cab gain" or whatever the hell the term is for it. You are dead on with the S10 peaking like hell at around 60hz. I HATE HATE peaky bass around 60-80hz, I like LOW, smooth bass which is why I was shooting for 27hz. You said I would want to tune higher in this situation but won't I be forced to set my high pass to appox the tuning of the enclosure and then I'd pretty much lose anything below that? A sub would be no fun if you couldn't hit the low note in "Put On." I'm a real noob to audio but trying hard to learn. Any help would be appreciated. So I don't have a clue as to what I should tune to if E30s are typical for peaking around 40 and 100hz. My driver is an Fi Q10 powered by a Sundown 1000D. Here are the specs of the driver:

DUAL 1 | DUAL 2 Fs: 34.1 Hz | 34.0 Hz Re: 0.70 Ohms/coil | 1.4 Ohms/coil Qms: 7.31 | 7.38 Qes: .37 | .37 Qts: .36 | .36 Mms: 230g | 2235g Cms: .88mm/N | .88mm/N Sd: 310cm^2 | 310cm^2 Vas: 11.8 l | 11.8 l Spl: 83.3dB 1W/1m | 83.2dB 1W/1m Bl: 13.9 N/A | 19.6 N/A Xmax: 28mm Rms: 1000W Sealed box: .2-.6 cuft HQTS Ported box: .5-1.2 cuft @ 28-33Hz Sub OD: 11.000” Cut ID: 9.250” Mounting depth: 6.500” Displacement: 0.12cuft

I don't know 3/4 of the stuff on that list means. What are your suggestions I try and tune to if you don't mind? Thanks!


Mike B.

[StereoInstaller1]

If you don't seal, there will be little tiny leaks. They make a little "chuffing" sound.

I glue carefully, (it is the glue that holds the parts together) and when I staple, I look for a timy bit of "squish", glue that has been squished out of the joint.

Dammit, all of this talk SO makes me wanna go set up the table saw!

I am gonna build some new home speakers soon. I am gonna do 3) 8" woofers on each side (Jamo, 12 ohm, like $8 each on clearance at PE) and run all 6 woofers on a 200 WPC Crown amp (like $200) at 4 ohms/channel, then use 2 Tang Band mids and those nice old Polk tweets I have sitting around and get busy building the AV cabinet that I have in my head and I gotta make desks and such for Kim and I and then....